(1) Field of the Invention
The present invention relates to a trailer hitch guide for aiding an automobile driver in positioning an automobile so that a coupling member associated with the automobile is aligned with a coupling member associated with a trailer to be towed. More specifically, the present invention relates to a trailer hitch guide for assisting in vertical, lateral, and longitudinal alignment of the automobile and trailer coupling members.
(2) Discussion of The Prior Art
Trailer hitch guides assist a driver in single-handedly maneuvering an automobile so that an automobile coupling member, ordinarily a hitch ball mounted upright adjacent the rear of an automobile or other towing vehicle, is positioned to mate with a trailer coupling member, ordinarily an inverted socket mounted facing downward in the hitch arm or tongue of the trailer. The correct mating position, or alignment, must be accomplished in a vertical, lateral, and longitudinal direction. Specifically, the ball must be below but adjacent the socket (vertical alignment), the ball must not be to either the left or right of the socket (lateral alignment), and the ball must not be either in front of or behind the socket (longitudinal alignment). The ball and socket are relatively small, and the task is further complicated because the driver ordinarily cannot see either coupling member from the driver compartment, when the members are within coupling range. If the driver is unskilled, the alignment operation can be very time consuming and frustrating, with much trial and error. And, even when the driver is highly skilled, such as a driver who regularly performs hitching operations as part of a business, several attempts and adjustments are typically necessary, significantly lowering efficiency.
Conventional trailer hitch guides employ visual aids associated with the automobile and trailer to help the driver align the coupling members. Various means are used to mount the visual aids on the vehicles to disclose to the driver the position of the ball relative to the socket. By maneuvering the automobile while observing the visual aids, the driver tries to move the ball into position under the socket with as few maneuvers as possible.
Prior art trailer guides are variously complex, difficult to install, or awkward to adjust, maintain, and use. Furthermore, the conventional guides may not transfer easily from one automobile-trailer pair to another, nor remove conveniently for storage. No prior art trailer guide combines the desirable features of simplicity, durability, ease of use, and economy of manufacture.
Tague U.S. Pat. No. 3,818,599 discloses two sighting components, each component consisting of a base having a magnet embedded in its bottom face, and an elongated extensible and contractible supporting rod mounted in the base. Each base is positioned on a metallic surface in the vicinity of the associated coupling assembly, and the tip of each rod is positioned directly above the associated coupling member at a predetermined distance above the ground. The driver moves the car until the tips coincide.
The Tague system is hard to operate. Because each base is mounted on a magnetic surface only adjacent the coupling member, rather than directly on or over the coupling member, the rod must be inclined so that the tip overhangs the coupling member. To position the tip directly over the coupling at a predetermined vertical distance calls for careful and time consuming adjustments, and a plumb line would appear necessary to get the precise positioning required. Also, the driver, while looking rearwardly, must move the automobile until the tips of the rods meet. This requires the driver to align two relatively small points, an awkward task at best. Furthermore, the sighting components of Tague are complex, requiring a telescopic rod and a machined base having means for allowing the rod to swing fore and aft for overhanging the coupling members.
Bohnet U.S. Pat. No. 3,015,162 discloses a sight member mounted over the hitch ball and a corresponding sight member mounted over the socket. A first sight member is supported by a bendable bracket having two legs at an approximate right angle. One leg is substantially horizontal and has a number of holes spaced along its length for receiving the first sight member, the member being placed in the hole most directly over the ball with the leg being bent as necessary to achieve the best alignment. The other, substantially vertical, leg of the bracket has a magnet for attaching the bracket to a car bumper. A second sight member is affixed by means of a bendable bracket to another magnet for positioning over the trailer socket.
The Bohnet device requires a number of adjustments for use. The sight member associated with the automobile is not mounted directly on the hitch ball, but rather on some metallic surface nearby, such as the bumper. The bracket must be properly bent and the correct hole selected for alignment of the sight member, and such alignment is unlimited by the number and spacing of the holes. Accordingly, the alignment over the hitch ball can be difficult to achieve. Proper alignment over the socket likewise depends on the bracket being properly bent and the magnet properly positioned. Therefore it is seen that adjustment of the sight members can not only be awkward and time consuming for a single trailer-towing vehicle pair, but can result in fatigue and failure where the device is employed for a number of such pairs, especially in a commercial setting.
Voelkerding et al. U.S. Pat. No. 3,765,703 discloses a hitch guide member mounted on the rear of an automobile, the guide having legs that diverge on either side of the hitch ball. The guide member can be adjusted heightwise. Two sighting members are placed on the guide member, one on each leg. A third sighting member is mounted above the socket on the trailer. The sighting members assist the driver in raising the socket to the proper height by means of a jack and subsequently in moving the car rearwardly so that the socket is guided into position between the guide member legs, the legs then forcibly guiding the socket member into final position.
The Voelkerding device is relatively difficult to build and install, requiring a number of parts, some of which are welded together. A mount for the hitch guide member must be attached to the automobile, and the hitch guide member therefore cannot be readily transferred to another vehicle without a corresponding mount. The sighting member on the socket is secured by means of a clip. Neither of the three sighting components is readily transferrable to another vehicle.
Whitehead U.S. Pat. No. 3,159,917, Folkins U.S. Pat. No. 3,363,318, and Anderson U.S. Pat. No. 3,702,029 all disclose complex and unwieldy mechanisms difficult to install, adjust, and use. The devices involve many parts, some of which must move with respect to others. Special tools are required for installation and maintenance. The complexity of these devices can be readily appreciated from a cursory review of FIGS. 1 through 13 of Whitehead, FIGS. 1 through 7 of Folkins, and FIGS. 1 through 4 of Anderson.
Whitehead discloses an elevation measuring device for gauging the height to which the socket must be raised to engage the ball. A rod is frictionally mounted to the side of the trailer and can be slid up and down to gauge the height of the trailer. A piece of tape is used to mark the proper height of the trailer on the rod before the trailer and automobile are separated. When re-coupling is desired, the proper height will still be recorded on the rod, and the socket can be raised accordingly. However, Whitehead contemplates that the proper height be recorded on the measuring rod before the vehicles are separated and does not disclose a method for adjusting the socket height without the pre-recording step.